The methanolic stem bark extract of Ficus thonningii (Moraceae) was subjected to preliminary phytochemical screening and in vitro antimicrobial tests. The phytochemical tests was carried out using standard methods of analysis and these investigations revealed the presence of alkaloids, anthraquinones, carbohydrates, flavonoids, saponins and tannins. The antimicrobial activity of the plant extract was assayed using the agar plate disc diffusion and nutrient broth dilution techniques. Test micro organisms were: Escherichia coli, Klebsiella spp, Pseudomonas aeruginosa, Salmonella typhi (Gram-negative), Staphylococcus aureus and Streptococcus spp. (Grampositive). The extracts inhibited the growth of all the test organisms at different concentrations especially againstPseudomonas aeruginosa and Streptococcus spp. which had mean inhibition zone of 33.33±7.33 mm and 32.33±2.51 mm respectively. The results showed the MIC of 10 mg ml -1 against pseudomonas and 1.25 against remaining organisms tested. The MBC against Staphylococcus aureus was 2.5 mg ml -1 and that of Streptococcus spp. was found to be 0.625mg ml -1 . The extracts showed varied inhibitory activity against the organisms studied.

Hair and nail samples were collected from different subjects with respect to sex, age of those working in iron welder workshop and liquor and non-liquor subject in Maiduguri Metropolis, Borno State, Nigeria for heavy metals determination. Sample collection and preparations were carried out using standard procedures. The levels of heavy metals (Copper (Cu), Zinc (Zn), Copper (Co), Manganese (Mn), Iron (Fe), Chromium (Cr), Cadmium (Cd) Arsenic (As), Nickel (Ni) and Lead (Pb)) were carried out using Atomic Absorption Spectrophotometer (AAS, Unicam 969). From the results of this study, Zn showed the highest concentrations while Cu showed the least levels. The results of the study showed that there was no contribution of liquor towards nail and hair metal concentrations. The levels of all the metals studied were significantly higher in the toenails compared to fingernails samples (p<0.05). Similarly, iron welding workers showed high concentrations of heavy metals when compared to liquor user. The levels of all the metals studied were statistically higher in male subjects compared to female subjects (p<0.05). The concentrations of heavy metals in nail samples were significantly higher when compared to hair samples. Significant levels of these metals in nail and hair samples indicate the presence of these metals in the environment and the workplace of the subjects. Since the present study reveals high levels of some heavy metals in hair and nail samples of iron welding worker volunteer. So there is instantaneous need for public awareness about the hazards of this occupation in order to enable these volunteer take necessary precautionary measures.

The Concentrations of organophosphorus pesticide residues (dichlorvos, diazinon, chlorpyrifos, and fenitrothion) were determine in some vegetables (spinach, lettuce, cabbage, tomato and onion) and soil samples from different depths within Alau Dam and Gongulong agricultural areas in Borno State, Nigeria. Samples collection and preparation were carried out using standard procedures. The concentrations of all the pesticides in the vegetables and soil samples were determined using GC/MS SHIMADZU (GC-17A) equipped with electron capture detector (ECD). The highest concentrations of diclorvos, diazinon, chlorpiryfos and fenithrothion in the Alau Dam and Gongulong agricultural areas were observed in the leaf of tomato, while the lowest concentrations were observed in the root of spinach. The concentrations of all the pesticides in the soil samples were observed to be higher at a depth of 21-30cm, while the lowest concentrations were observed at a depth of 0-10cm. The concentrations of all the organophosphorus pesticides in the vegetables and soil samples from the two agricultural areas were observed to be at alarming levels, much higher than the maximum residue limits (MRLs) and acceptable daily intake values (ADIs) set for vegetables and soil by the Cordex 2009 (WHO and FAO). The occurrence of pesticides in the vegetables and soil samples is a major threat to human that depends on these vegetables as food. Hence, the need for continuous monitoring is recommended so as to regulate the used of this pesticide in the study areas.

An analysis of intestine, liver, stomach and gill tissue concentrations of heavy metals (Cu, Co, Pb, Cr, Mn, Fe, Ni, Cd and Zn) in three commercially important fish species (Tilapia gallier, Crarias lazera and Osteoglossidae. caught within Alau Dam between the periods of January to August, 2007. These heavy metals were determined using Perkin-Elmer AAnalyst 300 Atomic Absorption Spectroscopy (AAS). Heavy metals contents varied significantly (p>0.05) depending on the fish species and on the types of tissues. The concentration of heavy metals in livers and gills tissue were relatively higher than the intestine and stomach tissues of the three species. The distribution of copper and cobalt were in the order of gills>stomach>liver>intestine in the entire fish samples, while the distribution of (Pb, Cr, Mn, Fe, Ni, Cd and Zn) were in the order of liver>gills>stomach>intestine. The concentrations of the entire elements in the three species were within tolerance limits that are safe for human consumption, with exception of lead in gills.

The purpose of this research is to determine the levels of some physicochemical parameters in water and sediment samples from Kwantan turare in Lake Chad, Baga, Borno State, Nigeria. Water samples were collected from five point designated as S₁ to S₅ for the determination of biochemical oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO) total dissolved solid (TDS), total suspended solid (TSS) anions and trace element. Sediment samples were also collected for the determination of heavy metals and total organic carbon (TOC). These parameters were determined using approved standard procedures. The levels of heavy metals in the water and sediment samples were determined using atomic absorption spectrophotometer (AAS). The concentrations of DO, BOD, COD, TSS, TDS, TOC, nitrite, nitrate, Phosphate, Sulphate, and Chloride in the water samples from the five sampling point were higher than the WHO limits for the protection of fish and other aquatic life. The concentrations of Fe, Mn, Cu, Cd, Pb, Ni and Co in the water samples were higher than the WHO guideline limits, indicating severed pollution of this portion of Lake Chad. This high level of heavy metals in the water samples is expected owing to runoff of wastewater from agricultural activities within the study area. However, the concentrations of all the metals in the sediment samples were higher than the recommended values stipulated by WHO; indicating that the sediment samples from this portion of Lake Chad were also polluted by heavy metals. Results of Analysis of variance (ANOVA) revealed that the concentrations of all the parameters studied were statistically significant among the sampling points. The prolonged presence of heavy metals in the water and sediment samples from this portion of Lake Chad give course for concern with time. The results of the study implies that continuous monitoring has to be carried out to ascertain the long-term impact of anthropogenic inputs to take remedial measures so as to ensure the health of aquatic life